Zum Störfallverhalten des HTR-100 : eine risikoorientierte Analyse

Mertens, J.

Report

FZJ-2016-06605

Zum Störfallverhalten des HTR-100 : eine risikoorientierte Analyse

Mertens, J. (Editor)FZJ*

1988
Kernforschungsanlage Jülich

Jülich : Kernforschungsanlage, Spezielle Berichte der Kernforschungsanlage Jülich 477, VI, 101 p. (1988)

Please use a persistent id in citations: http://hdl.handle.net/2128/12974

Report No.: Juel-Spez-0477

Abstract: In a risk-oriented analysis the accident behaviour of the HTR-100 was studied, the safety concept was analysed with respect to its balance, and the radiological risk was classified and quantified. Transients, leaks at the primary circuit, leaks at the steam generator and earthquakes were taken into account as initiating events. The analysis was performed in close interrelation with the planning process and provided indications of improvements to the accident control concept. Accidents involving loss of afterheat removal only contribute insignificantly to the radiological risk of the HTR-100 since cooling of the fuel elements sufficing to retain fission products is largely self-supporting. Essential contributions are made, on the other hand, by sequences initiated by a leak in a heating tube of the steam generator; its perational plate out acitivity may in part be released into the environment, possibly accompanied by fission gases from defective fuel particles. Leaks at the primary circuit are of comparable relevance; their radiological source term is significantly lower, but their frequency is higher. The risk contribution possibly caused by earthquakes proved to be negligible. In all cases emissions are so small that calculations of accident consequences do not reveal any lethal doses and practically no stochastic case of death due to cancer, and this without any immediate protection measures, long-term resettlement or decontamination. The integral risk of late fatalities is in the order of 1O$^{-7}$ per plant year; a number of sufficiently rare accident sequences provide contributions of the same order of magnitude. The doses from sequences possibly to be defined as design basis accidents remain far below the corresponding accident planning values.

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